Difference between revisions of "Thermodynamics"
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The number of moles in each phase (liquid or vapor) can be obtained from the lever rule: | The number of moles in each phase (liquid or vapor) can be obtained from the lever rule: | ||
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Revision as of 07:24, 26 April 2019
Two-component vapor-liquid equilibrium
Phase diagram of an ideal solution at fixed temperature
The following plot shows the vapor-liquid phase diagram for a binary ideal mixture (components: A and B). The vapor pressures of the pure substances are [math]p_A^*[/math] and [math]p_B^*[/math], respectively.
The blue curve shows the vapor pressure [math]p[/math] of the mixture as a function of the mole fraction of A in the liquid [math]x_A^l[/math]:
[math]p=p_B^*+(p_A^*-p_B^*)x_A^l[/math]
The red curve shows the vapor pressure [math]p[/math] of the mixture as a function of the mole fraction of A in the vapor [math]x_A^v[/math]:
[math]p=\dfrac{p_A^*p_B^*}{p_A^*-(p_A^*-p_B^*)x_A^v}[/math]
In the example below [math]p_A^*=1[/math] (a.u.) and the value of [math]p_B^*[/math] can be changed moving the slider below.
The number of moles in each phase (liquid or vapor) can be obtained from the lever rule:
[math]n^lBK=n^vKR[/math]